Amy Crackhouse always sounded like she was trying to sound like someone else. She had no real soul, just a simulacrum of what other singers with soul actually sounded like. Comparing her to the artists she was imitating is like seeing some fat-assed Elvis impersonator at the county fair and saying, "Wow! This must be what it was really like to see The King in Vegas!"
Oh, and Hendrix, Joplin, Cobain and the others all revolutionized music in some way. Crackhouse was a cheap imitation. Her death is sad, but so are the deaths of thousands of people by drugs every year, and I don't see Crackhouse's fans lamenting them much.